digital electronics design

Ten bits is not that many more than eight, so a four-way conditional test may be simplest.

Use a PIC.

Two 16-bit D-A converters, a precision analog multiplier, wired as a divider, plus a 12-bit A-D, with 10-bit truncation. Superior. :>)

Two M27C801s. Quotient in

If the ouptut is obtained by around 500ms it is good enough.I dont want to use a microcontroller or anything because i feel that it would be an overkill.Also the quotient is good enough for me. Thanks Rangan snipped-for-privacy@gmail.com

The best 'circuit' to do this involves a microprocessor.

Graham

Ah, but that's the quotient. Let's say we also want the exact remainder, as a separate analog output....

Jon

So 20 input pins and 10 output pins? With pwr and gnd, 32 pins at least. An Atmel AT89S51-24 is $1.89 in ones, they have hundreds in stock right now. I believe it has enough pins, 40DIP, 44TQFP, 44PLCC all available, an internal oscillator so all you need is Vcc and gnd,

You will be hard pressed for cheaper or fewer parts or better availability in small numbers and all digital.

Jon

Digikey is where I was looking, as I posted. I should have noted who it was when I said 'they.' What surprised me about this particular part is that they are asking less than 6 cents/IOpin. That's about half of what I usually expect to see.

Jon

Ahhhh.... The good old 8051 family comes to the rescue. My fave ! Where do you get the 89S51 for $1.89 though ? I'm using some 89S52s ? IIRC at the moment on several projects and I pay rather more than that. From Farnell for sure admittedly.

Graham

Ok - I see it. That's an awesome price. I'll have to investigate using Digikey occasionally. Their site is rubbish compared to Farnell's though.

The Uk site gives £1.06 ea. Nice.

Now if I could find some other stuff to make the shipping worthwhile.....

Graham

I just pulled the data sheet from Atmel. The oscillator was listed at Digikey as being "Oscillator Type: Internal." See:

However, a quick skim and I now think the data sheet disagrees with Digikey. It looks like it needs a crystal. I should have guessed.

Well, that adds some cost and a part and there goes the 6 cents/IOpin.

Jon

A microcontroller is far and away the least expensive option.

Designing hardware maths is just plain *wrong*. Very component intensive and expensive. Potentially *very* fast but you don't need that.

Graham

Overkill ? Come-on, a division is not 'that' simple (compared to an AND or OR I mean, it's not _that_ difficult either). A simple 8 bit uC with integrated oscillator will do the trick. That cost very little, all you will need is that single component ! You will need a programmer but you can do one easily with some resitors, a buffer chip and your // port. As suggested, look at the Atmels, they have nice stuff.

I don't know any chip that do the division and building one from other chips, _that_ is overkill.

Regards,

Sylvain

I think the OP wants an off-the-shelf (OTS) solution.

Any kind of micro will require software programming and hardware programming, then it can be wired into his circuit.

Unless anyone here has this device already programmed with docs and application notes to wire it up and maybe a demo board in their back pocket......

It?s clear that Srinivasa is a beginner.

So the long answer is "No" its not available OTS, but it can easily be done if you are willing to learn a little and so some home work.

If Srinivasa is willing to learn, this is a good news group to ask questions about getting your ideas and projects working.

I am sure many here have already did a napkin design on how they would do it. ( I too have penciled out my own design I used and ATMega 32 :-) )

Good Luck Srinivasa , I hope you success with your project.

Donald

add a couple of 74F181s' to the shopping list !

martin

I normally use a resonator. Lower cost than a crytal and still accurate enough frequency for most purposes.

Some low cost 8051 variants have internal RC oscillators. Didn't reckon the

Graham

You don't really need a multiplier chip. If you use an ADC that takes an external reference you can do something like this:

Ka/b Vout ! /+!-- GND +------+---< ! ! ! \\-!-+----/\\/\\/--- (-Va) b ----- ! ! 10bits ! REF ! ---!!---+ ==========! ! ! ! !---/\\/\\/---- -----